/Engine/Source/Runtime/Engine/Classes/Kismet/KismetMathLibrary.h
Snaps a value to the nearest grid multiple. E.g., Location = 5.1, GridSize = 10.0 : return value = 10.0 If GridSize is 0 Location is returned if GridSize is very small precision issues may occur.
static double GridSnap_Float ( double Location, double GridSize )